1. Field of the Invention
The present invention relates to a method of separating sweet glycosides or non-glycosides from natural sweet extracts.
2. Description of the Prior Art
The natural sweet extracts can be obtained by extractions of leaves, roots or fruits of natural plants in the form of liquid or solid. Some natural sweet extracts have sweetness higher than saccharose. For examples, stevioside extracted from leaves of Stevia; glycyrrhizin extracted from root of Kanzo and phyllodulcin extracted from Amachia have sweetness of more than 300 times of sweetness. These natural sweet compounds are glycosides or non-glycosides having a molecular weight of about 250 to 1000.
It has been known to separate the natural sweet compounds from the extract obtained by extracting leaves, roots or fruits of plants by a gas-chromatography or a thin layer chromatography, etc. However, any satisfactory separating method has not been found.
In the gas-chromatography, it is necessary to convert the natural sweet compounds to the corresponding volatile compound by the trimethylsilylation or the Smith decomposition because the natural sweet compounds are involatile compounds.
On the other hand, in the thin layer chromatography, it is not enough to separate the natural sweet compound and it takes a long time for development separation.